A gene cluster is a group of two or more genes that are located close together on a chromosome and often share similar functions. These genes can be involved in related biological processes, such as the production of specific proteins or enzymes. The proximity of these genes allows for coordinated regulation, meaning they can be turned on or off together in response to certain signals. Gene clusters can play a significant role in evolution and genetic diversity. For example, in humans, certain gene clusters are responsible for the immune response, allowing for a more effective defense against pathogens. Understanding gene clusters helps researchers study genetic diseases and develop targeted therapies.